CompositeExclusionFilterFactory.java

/*
 *  This file is part of the Wayback archival access software
 *   (http://archive-access.sourceforge.net/projects/wayback/).
 *
 *  Licensed to the Internet Archive (IA) by one or more individual
 *  contributors.
 *
 *  The IA licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.archive.wayback.accesscontrol;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.logging.Logger;

import org.archive.wayback.resourceindex.filters.CompositeExclusionFilter;
import org.archive.wayback.resourceindex.filters.ExclusionFilter;

/**
 * Class that provides SearchResult Filtering based on multiple
 * ExclusionFilterFactory instances by returning a single composite
 * SearchResultFilter based on the results of each ExclusionFilter.
 *
 * @author brad
 */
public class CompositeExclusionFilterFactory implements ContextExclusionFilterFactory {

	private static final Logger LOGGER = Logger
		.getLogger(CompositeExclusionFilterFactory.class.getName());

	private ArrayList<ExclusionFilterFactory> factories = new ArrayList<ExclusionFilterFactory>();

	/**
	 * @param factory to be added to the composite
	 */
	public void addFactory(ExclusionFilterFactory factory) {
		factories.add(factory);
	}

	protected static ExclusionFilter getInstance(ExclusionFilterFactory factory, CollectionContext context) {
		if (factory instanceof ContextExclusionFilterFactory) {
			return ((ContextExclusionFilterFactory)factory).getExclusionFilter(context);
		} else {
			return factory.get();
		}
	}

	@Override
	public ExclusionFilter getExclusionFilter(CollectionContext context) {
		CompositeExclusionFilter filter = new CompositeExclusionFilter();
		for (ExclusionFilterFactory factory : factories) {
			ExclusionFilter memberFilter = getInstance(factory, context);
			if (memberFilter != null) {
				filter.addComponent(memberFilter);
			} else {
				LOGGER.warning("Skipping null filter returned from factory: " + factory);
			}
		}
		return filter;
	}

	/*
	 * (non-Javadoc)
	 *
	 * @see org.archive.wayback.resourceindex.ExclusionFilterFactory#get()
	 */
	public ExclusionFilter get() {
		return getExclusionFilter(null);
	}

	/**
	 * @return the factories
	 */
	public ArrayList<ExclusionFilterFactory> getFactories() {
		return factories;
	}

	/**
	 * @param factories the factories to set
	 */
	public void setFactories(ArrayList<ExclusionFilterFactory> factories) {
		this.factories = factories;
	}

	/*
	 * (non-Javadoc)
	 *
	 * @see org.archive.wayback.accesscontrol.ExclusionFilterFactory#shutdown()
	 */
	public void shutdown() {
		Iterator<ExclusionFilterFactory> itr = factories.iterator();
		while (itr.hasNext()) {
			ExclusionFilterFactory i = itr.next();
			i.shutdown();
		}
	}
}